Method and apparatus for heating rolls



G. FOX

METHOD AND APPARATUS FOR HEATING ROLLS Jan. 5 1926.

Filed June 4, 1923 Mwm 10 177 4&5

' Patented Jan. 5, 1926. I

UNITED STATES PATENT ori ice.

GORDON FOX, OF CHICAGO, ILLINOIS, ASSIGNOR T F-REYN ENGINEERING COMPANY,

01 CHICAGO, ILLINOIS, A CORPORATION OF MAINE.

-METHOD AND APPARATUS FOR HEATING ROLLS.

Application filed June 4, 1923. Serial No. 643,157.

. To all whom it may concern:

may not be unduly cool. In starting operations it is necessary to bringup the temperature of the rolls, this raising 'in temperature beingaccomplished in some instances by passing heated sheet formingbars'between the rolls. Steam, hot air, gas flame and other means havebeen employed for heating said rolls Another common method is to applyheating elements in metallic contact with the periphery of the rolls,the heat being transferred to the rolls byconduction.

utilizing the heat generate The lastmentioned method requires that therolls be stationary during the heating operation.

An object of the present invention is to.

provide means for efiiciently heating the rolls while said rolls are inrotation.

A further object is to provide means whereby heat is efficientlygenerated within the rolls themselves, V

A further object is to rovide means by vhysteresis and eddy currents inthe material of the rolls caused by the passage through the rolls of apulsating or alternating magnetic flux.

A further object is to provide a method of heating rolls, utilizing theheating effect of hysteresis and eddy currents.

Further objects will appear as the description proceeds. I I i The onefigure of the drawin represents diagrammatically the principle presentinvention. 1

The numeral 1 indicates a frame, which provides bearings for a pair ofrolls '22. The frame 1' may be slidably mounted upon the tracks 33 forthe purpose of permits of the ting longitudinal movement ofthe frame 1and the rolls 2-2,

The rolls 22 are ordinarily made of metallic material and are ofunlaminated.

construction --whereby they will generate considerable heat it placed inan alternating or pulsating field of flux. the rolls as ordinarilyconstructed is utilized.

This feature of and practiced in the present invention -for generatingthe heat required for proper operation. Each of the rolls 22 hasassociated therewith an electromagnet 4. Each electromagnet 4, indicatedas being of U:

shaped conformation, embraces a chord of .its corresponding roll 2,whereby each electromagnet 4 and its corresponding roll 2 form a circuitfor magnetic flux, closed except for the gap between the poles of theelectromagnet and the periphery of the roll. The solenoids for supplyingthe fields of flux to the electromagnets 44 are indicated by thenumerals 55. Each solenoid will be connected to a source of pulsatingoralternating current: of rapidly changing magnitude, whereby pulsatingor alternating flux of rapidly changing magnitude will beset up in theelectromagnets 4-4 and rolls 2-2.

The mode of operation of the above described embodiment of thepresent'invention will be clear without detailed description. Thealternating or pulsating circuit set up in each of the rolls 2-2 willgenerate the necessary heat either for the preliminary heating of therolls or for maintaining the desired temperature during operation.

It will be understood, of course, that many modifications may be made inthe structure illustrated and in the method of vusing same. It isintended in this patent to cover all such modifications that fall withinthe scope of the invention as defined by the appended claims.

What is claimed is:

1. The method of heating the rolls of a sheet mill, which comprisespassing a magv netic flux of rapidly changing magnitude r and directionthrough rolls made of unlamlnated magnetic material.

2. Rolllng mill construction, comprising a pair of juxtaposed rolls ofmagnetic material, and a pair of U-shaped magnets for directing fluxthrough the material of said rolls, said electromagnets having means for5 setting up rapidly changing magnetic flux therein.

3. A rolling mill, comprising a rotatmg roll of magnetic material and astationary U-shaped magnet closely associated therewith for directingmagnetic flux of rapidly 10 changing magnitude through said roll.

Signed at Chicago, Illinois, this 31 day of May, 1923.

GORDON FOX.

